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EPA25DeterminationOfTotalGaseousNonmethaneOrganicEmissionsAsCarbon_其它国外.rar
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EPA 25 Determination Of Total
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EPA25DeterminationOfTotalGaseousNonmethaneOrganicEmissionsAsCarbon_其它国外.rar,EPA 25 Determination Of Total,Gaseous
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1201METHOD 25 - DETERMINATION OF TOTAL GASEOUS NONMETHANEORGANIC EMISSIONS AS CARBON1.0 Scope and Application.1.1 Analytes.AnalyteCAS No.SensitivityTotal gaseous nonmethaneorganic compounds(TGNMO)N/ADependent uponanalytical equipment1.2 Applicability.1.2.1 This method is applicable for the determinationof volatile organic compounds (VOC) (measured as totalgaseous nonmethane organics (TGNMO) and reported as carbon)in stationary source emissions. This method is notapplicable for the determination of organic particulatematter.1.2.2 This method is not the only method that appliesto the measurement of VOC. Costs, logistics, and otherpracticalities of source testing may make other test methodsmore desirable for measuring VOC contents of certaineffluent streams. Proper judgment is required indetermining the most applicable VOC test method. Forexample, depending upon the molecular composition of theorganics in the effluent stream, a totally automatedsemicontinuous nonmethane organics (NMO) analyzer interfaceddirectly to the source may yield accurate results. This1202approach has the advantage of providing emission datasemicontinuously over an extended time period.1.2.3 Direct measurement of an effluent with a flameionization detector (FID) analyzer may be appropriate withprior characterization of the gas stream and knowledge thatthe detector responds predictably to the organic compoundsin the stream. If present, methane (CH4) will, of course,also be measured. The FID can be used under any of thefollowing limited conditions: (1) where only one compound isknown to exist; (2) when the organic compounds consist ofonly hydrogen and carbon; (3) where the relative percentagesof the compounds are known or can be determined, and the FIDresponses to the compounds are known; (4) where a consistentmixture of the compounds exists before and after emissioncontrol and only the relative concentrations are to beassessed; or (5) where the FID can be calibrated againstmass standards of the compounds emitted (solvent emissions,for example).1.2.4 Another example of the use of a direct FID isas a screening method. If there is enough informationavailable to provide a rough estimate of the analyzeraccuracy, the FID analyzer can be used to determine the VOCcontent of an uncharacterized gas stream. With a sufficientbuffer to account for possible inaccuracies, the direct FID1203can be a useful tool to obtain the desired results withoutcostly exact determination.1.2.5 In situations where a qualitative/quantitativeanalysis of an effluent stream is desired or required, a gaschromatographic FID system may apply. However, for sourcesemitting numerous organics, the time and expense of thisapproach will be formidable.2.0 Summary of Method.2.1 An emission sample is withdrawn from the stack ata constant rate through a heated filter and a chilledcondensate trap by means of an evacuated sample tank. Aftersampling is completed, the TGNMO are determined byindependently analyzing the condensate trap and sample tankfractions and combining the analytical results. The organiccontent of the condensate trap fraction is determined byoxidizing the NMO to carbon dioxide (CO2) and quantitativelycollecting in the effluent in an evacuated vessel; then aportion of the CO2 is reduced to CH4 and measured by an FID. The organic content of the sample tank fraction is measuredby injecting a portion of the sample into a gaschromatographic column to separate the NMO from carbonmonoxide (CO), CO2, and CH4; the NMO are oxidized to CO2,reduced to CH4, and measured by an FID. In this manner, the1204variable response of the FID associated with different typesof organics is eliminated.3.0 Definitions. Reserved4.0 Interferences. 4.1 Carbon Dioxide and Water Vapor. When carbondioxide (CO2) and water vapor are present together in thestack, they can produce a positive bias in the sample. Themagnitude of the bias depends on the concentrations of CO2and water vapor. As a guideline, multiply the CO2concentration, expressed as volume percent, times the watervapor concentration. If this product does not exceed 100,the bias can be considered insignificant. For example, thebias is not significant for a source having 10 percent CO2and 10 percent water vapor, but it might be significant fora source having 10 percent CO2 and 20 percent water vapor.4.2. Particulate Matter. Collection of organicparticulate matter in the condensate trap would produce apositive bias. A filter is included in the samplingequipment to minimize this bias.5.0 Safety.5.1 Disclaimer. This method may involve hazardousmaterials, operations, and equipment. This test method maynot address all of the safety problems associated with itsuse. It is the responsibility of the user of this test1205method to establish appropriate safety and health practicesand determine the applicability of regulatory limitationsprior to performing this test method.6.0 Equipment and Supplies.6.1 Sample Collection. The sampling system consistsof a heated probe, heated filter, condensate trap, flowcontrol system, and sample tank (see Figure 25-1). The TGNMOsampling equipment can be constructed from commerciallyavailable components and components fabricated in a machineshop. The following equipment is required:6.1.1 Heated Probe. 6.4-mm (-in.) OD stainlesssteel tubing with a heating system capable of maintaining agas temperature at the exit end of at least 129EC (265EF). The probe shall be equipped with a temperature sensor at theexit end to monitor the gas temperature. A suitable probeis shown in Figure 25-1. The nozzle is an elbow fittingattached to the front end of the probe while the temperaturesensor is inserted in the side arm of a tee fitting attachedto the rear of the probe. The probe is wrapped with asuitable length of high temperature heating tape, and thencovered with two layers of glass cloth insulation and onelayer of aluminum foil or an equivalent wrapping.1206NOTE: If it is not possible to use a heating systemfor safety reasons, an unheated system with an in-stackfilter is a suitable alternative.6.1.2 Filter Holder. 25-mm (15/16-in.) ID Gelmanfilter holder with 303 stainless steel body and 316stainless steel support screen with the Viton O-ringreplaced by a Teflon O-ring. 6.1.3 Filter Heating System.6.1.3.1 A metal box consisting of an inner and anouter shell separated by insulating material with a heatingelement in the inner shell capable of maintaining a gastemperature at the filter of 121 3 EC (250 5 EF). Theheating box shall include temperature sensors to monitor thegas temperature immediately upstream and immediatelydownstream of the filter.6.1.3.2 A suitable heating box is shown in Figure 25-2. The outer shell is a metal box that measures 102 mm x280 mm x 292 mm (4 in. x 11 in. x 11 in.), while the innershell is a metal box measuring 76 mm x 229 mm x 241 mm (3in. x 9 in. x 9 in.). The inner box is supported by 13-mm(-in.) phenolic rods. The void space between the boxes isfilled with ceramic fiber insulation which is sealed inplace by means of a silicon rubber bead around the uppersides of the box. A removable lid made in a similar manner,1207with a 25-mm (1-in.) gap between the parts is used to coverthe heating chamber. The inner box is heated with a 250-watt cartridge heater, shielded by a stainless steel shroud. The heater is regulated by a thermostatic temperaturecontroller which is set to maintain a gas temperature of 121EC (250 EF) as measured by the temperature sensor upstreamof the filter. NOTE: If it is not possible to use a heating systemfor safety reasons, an unheated system with an in-stackfilter is a suitable alternative.6.1.4 Condensate Trap. 9.5-mm (d-in.) OD 316stainless steel tubing bent into a U-shape. Exactdimensions are shown in Figure 25-3. The tubing shall bepacked with coarse quartz wool, to a density ofapproximately 0.11 g/cm3 before bending. While thecondensate trap is packed with dry ice in the Dewar, an icebridge may form between the arms of the condensate trapmaking it difficult to remove the condensate trap. Thisproblem can be prevented by attaching a steel plate betweenthe arms of the condensate trap in the same plane as thearms to completely fill the intervening space.6.1.5 Valve. Stainless steel control valve forstarting and stopping sample flow.12086.1.6 Metering Valve. Stainless steel valve forregulating the sample flow rate through the sample train.6.1.7 Rate Meter. Rotameter, or equivalent, capableof measuring sample flow in the range of 60 to 100 cm3/min(0.13 to 0.21 ft3/hr).6.1.8 Sample Tank. Stainless steel or aluminum tankwith a minimum volume of 4 liters (0.14 ft3).NOTE: Sample volumes greater than 4 liters may berequired for sources with low organic concentrations.6.1.9 Mercury Manometer. U-tube manometer orabsolute pressure gauge capable of measuring pressure towithin 1 mm Hg in the range of 0 to 900 mm.6.1.10 Vacuum Pump. Capable of evacuating to anabsolute pressure of 10 mm Hg.6.2 Condensate Recovery. The system for the recoveryof the organics captured in the condensate trap consists ofa heat source, an oxidation catalyst, a nondispersiveinfrared (NDIR) analyzer, and an intermediate collectionvessel (ICV). Figure 25-4 is a schematic of a typicalsystem. The system shall be capable of proper oxidation andrecovery, as specified in Section 10.1.1. The followingmajor components are required:6.2.1 Heat Source. Sufficient to heat the condensatetrap (including probe) to a temperature of 200 EC (390 EF). 1209A system using both a heat gun and an electric tube furnaceis recommended.6.2.2 Heat Tape. Sufficient to heat the connectingtubing between the water trap and the oxidation catalyst to100 EC (212 EF).6.2.3 Oxidation Catalyst. A suitable length of 9.5mm (d-in.) OD Inconel 600 tubing packed with 15 cm (6 in.)of 3.2 mm (c-in.) diameter 19 percent chromia on aluminapellets. The catalyst material is packed in the center ofthe catalyst tube with quartz wool packed on either end tohold it in place. 6.2.4 Water Trap. Leak-proof, capable of removingmoisture from the gas stream.6.2.5 Syringe Port. A 6.4-mm (-in.) OD stainlesssteel tee fitting with a rubber septum placed in the sidearm.6.2.6 NDIR Detector. Capable of indicating CO2concentration in the range of zero to 5 percent, to monitorthe progress of combustion of the organic compounds from thecondensate trap.6.2.7 Flow-Control Valve. Stainless steel, tomaintain the trap conditioning system near atmosphericpressure.6.2.8 Intermediate Collection Vessel. Stainlesssteel or aluminum, equipped with a female quick connect. 1210Tanks with nominal volumes of at least 6 liters (0.2 ft3)are recommended.6.2.9 Mercury Manometer. Same as described in Section6.1.9.6.2.10 Syringe. 10-ml gas-tight glass syringeequipped with an appropriate needle.6.2.11 Syringes. 10-l and 50-l liquid injectionsyringes.6.2.12 Liquid Sample Injection Unit. 316 Stainlesssteel U-tube fitted with an injection septum (seeFigure 25-7).6.3 Analysis.6.3.1 NMO Analyzer. The NMO analyzer is a gaschromatograph (GC) with backflush capability for NMOanalysis and is equipped with an oxidation catalyst,reduction catalyst, and FID. Figures 25-5 and 25-6 areschematics of a typical NMO analyzer. This semicontinuousGC/FID analyzer shall be capable of: (1) separating CO, CO2,and CH4 from NMO, (2) reducing the CO2 to CH4 and quantifyingas CH4, and (3) oxidizing the NMO to CO2, reducing the CO2 toCH4 and quantifying as CH4, according to Section 10.1.2. The analyzer consists of the following major components:6.3.1.1 Oxidation Catalyst. A suitable length of9.5-mm (d-in.) OD Inconel 600 tubing packed with 5.1 cm (2in.) of 19 percent chromia on 3.2-mm (c-in.) alumina1211pellets. The catalyst material is packed in the center ofthe tube supported on either side by quartz wool. Thecatalyst tube must be mounted vertically in a 650 EC (1200EF) furnace. Longer catalysts mounted horizontally may beused, provided they can meet the specifications of Section10.1.2.1.6.3.1.2 Reduction Catalyst. A 7.6-cm (3-in.) lengthof 6.4-mm (-in.) OD Inconel tubing fully packed with 100-mesh pure nickel powder. The catalyst tube must be mountedvertically in a 400 EC (750 EF) furnace.6.3.1.3 Separation Column(s). A 30-cm (1-ft) lengthof 3.2-mm (c-in.) OD stainless steel tubing packed with60/80 mesh Unibeads 1S followed by a 61-cm (2-ft) length of3.2-mm (c-in.) OD stainless steel tubing packed with 60/80mesh Carbosieve G. The Carbosieve and Unibeads columns mustbe baked separately at 200 EC (390 EF) with carrier gasflowing through them for 24 hours before initial use.6.3.1.4 Sample Injection System. A single 10-port GCsample injection valve or a group of valves with sufficientports fitted with a sample loop properly sized to interfacewith the NMO analyzer (1-cc loop recommended).6.3.1.5 FID. An FID meeting the followingspecifications is required:12126.3.1.5.1 Linearity. A linear response (5 percent)over the operating range as demonstrated by the proceduresestablished in Section 10.1.2.3.6.3.1.5.2 Range. A full scale range of 10 to 50,000ppm CH4. Signal attenuators shall be available to produce aminimum signal response of 10 percent of full scale.6.3.1.6 Data Recording System. Analog strip chartrecorder or digital integration system compatible with theFID for permanently recording the analytical results.6.3.2 Barometer. Mercury, aneroid, or otherbarometer capable of measuring atmospheric pressure towithin 1 mm Hg.6.3.3 Temperature Sensor. Capable of measuring thelaboratory temperature within 1 EC (2 EF).6.3.4 Vacuum Pump. Capable of evacuating to anabsolute pressure of 10 mm Hg.7.0 Reagents and Standards.7.1 Sample Collection. The following reagents arerequired for sample collection:7.1.1 Dry Ice. Solid CO2, crushed.7.1.2 Coarse Quartz Wool. 8 to 15 m.7.1.3 Filters. Glass fiber filters, without organicbinder.12137.2 NMO Analysis. The following gases are requiredfor NMO analysis:7.2.1 Carrier Gases. helium (He) and oxygen (O2)containing less than 1 ppm CO2 and less than 0.1 ppm hydrocarbon.7.2.2 Fuel Gas. Hydrogen (H2), at least 99.999percent pure.7.2.3 Combustion Gas. Either air (less than 0.1 ppmtotal hydrocarbon content) or O2 (purity 99.99 percent orgreater), as required by the detector.7.3 Condensate Analysis. The following are requiredfor condensate analysis:7.3.1 Gases. Containing less than 1 ppm carbon.7.3.1.1 Air.7.3.1.2 Oxygen.7.3.2 Liquids. To conform to the specificationsestablished by the Committee on Analytical Reagents of theAmerican Chemical Society.7.3.2.1 Hexane.7.3.2.2 Decane.7.4 Calibration. For all calibration gases, themanufacturer must recommend a maximum shelf life for eachcylinder (i.e., the length of time the gas concentration isnot expected to change more than 5 percent from its1214certified value). The date of gas cylinder preparation,certified organic concentration, and recommended maximumshelf life must be affixed to each cylinder before shipmentfrom the gas manufacturer to the buyer. The followingcalibration gases are required:7.4.1 Oxidation Catalyst Efficiency Check CalibrationGas. Gas mixture standard with nominal concentration of 1percent methane in air.7.4.2 FID Linearity and NMO Calibration Gases. Threegas mixture standards with nominal propane concentrations of20 ppm, 200 ppm, and 3000 ppm, in air.7.4.3 CO2 Calibration Gases. Three gas mixturestandards with nominal CO2 concentrations of 50 ppm, 500ppm, and 1 percent, in air. NOTE: Total NMO less than 1 ppm required for 1percent mixture.7.4.4 NMO Analyzer System Check Calibration Gases. Four calibration gases are needed as follows:7.4.4.1 Propane Mixture. Gas mixture standardcontaining (nominal) 50 ppm CO, 50 ppm CH4, 1 percent CO2,and 20 ppm C3H8, prepared in air.7.4.4.2 Hexane. Gas mixture standard containing(nominal) 50 ppm hexane in air.12157.4.4.3 Toluene. Gas mixture standard containing(nominal) 20 ppm toluene in air.7.4.4.4 Methanol. Gas mixture standard containing(nominal) 100 ppm methanol in air.7.5 Quality Assurance Audit Samples. 7.5.1 It is recommended, but not required, that aperformance audit sample be analyzed in conjunction with thefield samples. The audit sample should be in a suitablesample matrix at a concentration similar to the actual fieldsamples.7.5.2 When making compliance determinations, and uponavailability, audit samples may be obtained from theappropriate EPA Regional Office or from the responsibleenforcement authority and analyzed in conjunction with thefield samples.NOTE: The responsible enforcement authority should benotified at least 30 days prior to the test date to allowsufficient time for sample delivery.8.0 Sample Collection, Preservation, Transport, andStorage.8.1 Sampling Equipment Preparation.8.1.1 Condensate Trap Cleaning. Before its initialuse and after each use, a condensate trap should bethoroughly cleaned and checked to ensure that it is not1216contaminated. Both cleaning and checking can beaccomplished by installing the trap in the condensaterecovery system and treating it as if it were a sample. Thetrap should be heated as described in Section 11.1.3. Atrap may be considered clean when the CO2 concentration inits effluent gas drops below 10 ppm. This check is optionalfor traps that most recently have been used to collectsamples which were then recovered according to the procedurein Section 11.1.3.8.1.2 Sample Tank Evacuation and Leak-Check. Evacuate the sample tank to 10 mm Hg absolute pressure orless. Then close the sample tank valve, and allow the tankto sit for 60 minutes. The tank is acceptable if a changein tank vacuum of less than 1 mm Hg is noted. Theevacuation and leak-check may be conducted either in thelaboratory or the field.8.1.3 Sampling Train Assembly. Just before assembly,measure the tank vacuum using a mercury manometer. Recordthis vacuum, the ambient temperature, and the barometricpressure at this time. Close the sample tank valve andassemble the sampling system as shown in Figure 25-1. Immerse the condensate trap body in dry ice at least 30minutes before commencing sampling to improve collectionefficiency. The point where the inlet tube joins the trap1217body should be 2.5 to 5 cm (1 to 2 in.) above the top of thedry ice.8.1.4 Pretest Leak-Check. A pretest leak-check isrequired. Calculate or measure the approximate volume ofthe sampling train from the probe tip to the sample tankvalve. After assembling the sampling train, plug the probetip, and make certain that the sample tank valve is closed. Turn on the vacuum pump, and evacuate the sampling systemfrom the probe tip to the sample tank valve to an absolutepressure of 10 mm Hg or less. Close the purge valve, turnoff the pump, wait a minimum period of 10 minutes, andrecheck the indicated vacuum. Calculate the maximumallowable pressure change based on a leak rate of 1 percentof the sampling rate using Equation 25-1, Section 12.2. Ifthe measured pressure change exceeds the allowable, correctthe problem and repeat the leak-check before beginningsampling.8.2 Sample Collection.8.2.1 Unplug the probe tip, and place the probe intothe stack such that the probe is perpendicular to the ductor stack axis; locate the probe tip at a single preselectedpoint of average velocity facing away from the direction ofgas flow. For stacks having a negative static pressure,seal the sample port sufficiently to prevent air in-leakagearound the probe. Set the probe temperature controller to1218129 EC (265 EF) and the filter temperature controller to 121EC (250 EF). Allow the probe and filter to heat for about30 minutes before purging the sample train.8.2.2 Close the sample valve, open the purge valve,and start the vacuum pump. Set the flow rate between 60 and100 cm3/min (0.13 and 0.21 ft3/hr), and purge the train withstack gas for at least 10 minutes.8.2.3 When the temperatures at the exit ends of theprobe and filter are within the corresponding specifiedranges, check the dry ice level around the condensate trap,and add dry ice if necessary. Record the clock time. Tobegin sampling, close the purge valve and stop the pump. Open the sample valve and the sample tank valve. Using theflow control valve, set the flow through the sample train tothe proper rate. Adjust the flow rate as necessary tomaintain a constant rate (10 percent) throughout theduration of the sampling period. Record the sample tankvacuum and flowmeter setting at 5-minute intervals. (SeeFigure 25-8.) Select a total sample time greater than orequal to the minimum sampling time specified in theapplicable subpart of the regulations; end the sampling whenthis time period is reached or when a constant flow rate canno longer be maintained because of reduced sample tankvacuum.1219NOTE: If sampling had to be stopped before obtainingthe minimum sampling time (specified in the applicablesubpart) because a constant flow rate could not bemaintained, proceed as follows: After closing the sampletank valve, remove the used sample tank from the samplingtrain (without disconnecting other portions of the samplingtrain). Take another evacuated and leak-checked sampletank, measure and record the tank vacuum, and attach the newtank to the sampling train. After the new tank is attachedto the sample train, proceed with the sampling until therequired minimum sampling time has been exceeded.8.3 Sample Recovery. After sampling is completed,close the flow control valve, and record the final tankvacuum; then record the tank temperature and barometricpressure. Close the sample tank valve, and disconnect thesample tank from the sample system. Disconnect thecondensate trap at the inlet to the rate meter, and tightlyseal both ends of the condensate trap. Do not include theprobe from the stack to the filter as part of the condensatesample.8.4 Sample Storage and Transport. Keep the trappacked in dry ice until the samples are returned to thelaboratory for analysis. Ensure that run numbers areidentified on the condensate trap and the sample tank(s).12209.0 Quality Control.SectionQuality ControlMeasureEffect10.1.1Initial performancecheck of condensaterecovery apparatusEnsure acceptablecondensate recoveryefficiency10.1.2,10.2NMO analyzer initialand daily performancechecksEnsure precision ofanalytical results11.3Audit Sample AnalysesEvaluate analyticaltechnique andinstrument calibration10.0 Calibration and Standardization.NOTE: Maintain a record of performance of each item.10.1 Initial Performance Checks.10.1.1 Condensate Recovery Apparatus. Perform thesetests before the system is first placed in operation, afterany shutdown of 6 months or more, and after any majormodification of the system, or at the frequency recommendedby the manufacturer.10.1.1.1 Carrier Gas and Auxiliary O2 Blank Check. Analyze each new tank of carrier gas or auxiliary O2 withthe NMO analyzer to check for contamination. Treat the gascylinders as noncondensible gas samples, and analyzeaccording to the procedure in Section 11.2.3. Add togetherany measured CH4, CO, CO2, or NMO. The total concentrationmust be less than 5 ppm.10.1.1.2 Oxidation Catalyst Efficiency Check.122110.1.1.2.1 With a clean condensate trap installed inthe recovery system or a 1/8 stainless steel connectortube, replace the carrier gas cylinder with the high levelmethane standard gas cylinder (Section 7.4.1). Set thefour-port valve to the recovery position, and attach an ICVto the recovery system. With the sample recovery valve invent position and the flow-control and ICV valves fullyopen, evacuate the manometer or gauge, the connectingtubing, and the ICV to 10 mm Hg absolute pressure. Closethe flow-control and vacuum pump valves.10.1.1.2.2 After the NDIR response has stabilized,switch the sample recovery valve from vent to collect. Whenthe manometer or pressure gauge begins to register a slightpositive pressure, open the flow-control valve. Keep theflow adjusted such that the pressure in the system ismaintained within 10 percent of atmospheric pressure. Continue collecting the sample in a normal manner until theICV is filled to a nominal gauge pressure of 300 mm Hg. Close the ICV valve, and remove the ICV from the system. Place the sample recovery valve in the vent position, andreturn the recovery system to its normal carrier gas andnormal operating conditions. Analyze the ICV for CO2 usingthe NMO analyzer; the catalyst efficiency is acceptable ifthe CO2 concentration is within 2 percent of the methanestandard concentration.122210.1.1.3 System Performance Check. Construct aliquid sample injection unit similar in design to the unitshown in Figure 25-7. Insert this unit into the condensaterecovery and conditioning system in place of a condensatetrap, and set the carrier gas and auxiliary O2 flow rates tonormal operating levels. Attach an evacuated ICV to thesystem, and switch from system vent to collect. With thecarrier gas routed through the injection unit and theoxidation catalyst, inject a liquid sample (see Sections10.1.1.3.1 to 10.1.1.3.4) into the injection port. Operatethe trap recovery system as described in Section 11.1.3. Measure the final ICV pressure, and then analyze the vesselto determine the CO2 concentration. For each injection,calculate the percent recovery according to Section 12.7. Calculate the relative standard deviation for each set oftriplicate injections according to Section 12.8. Theperformance test is acceptable if the average percentrecovery is 100 5 percent and the relative standarddeviation is less than 2 percent for each set of triplicateinjections.10.1.1.3.1 50 l hexane.10.1.1.3.2 10 l hexane.10.1.1.3.3 50 l decane.10.1.1.3.4 10 l decane.122310.1.2 NMO Analyzer. Perform these tests before thesystem is first placed in operation, after any shutdownlonger than 6 months, and after any major modification ofthe system.10.1.2.1 Oxidation Catalyst Efficiency Check. Turnoff or bypass the NMO analyzer reduction catalyst. Maketriplicate injections of the high level methane standard(Section 7.4.1). The oxidation catalyst operation isacceptable if the FID response is less than 1 percent of theinjected methane concentration.10.1.2.2 Reduction Catalyst Efficiency Check. Withthe oxidation catalyst unheated or bypassed and the heatedreduction catalyst bypassed, make triplicate injections ofthe high level methane standard (Section 7.4.1). Repeatthis procedure with both catalysts operative. The reductioncatalyst operation is acceptable if the responses under bothconditions agree within 5 percent of their average.10.1.2.3 NMO Analyzer Linearity Check Calibration. While operating both the oxidation and reduction catalysts,conduct a linearity check of the analyzer using the propanestandards specified in Section 7.4.2. Make triplicateinjections of each calibration gas. For each gas (i.e.,each set of triplicate injections), calculate the averageresponse factor (area/ppm C) for each gas, as well as and1224the relative standard deviation (according to Section 12.8). Then calculate the overall mean of the response factorvalues. The instrument linearity is acceptable if theaverage response factor of each calibration gas is within2.5 percent of the overall mean value and if the relativestandard deviation gas is less than 2 percent of the overallmean value. Record the overall mean of the propane responsefactor values as the NMO calibration response factor (RFNMO).Repeat the linearity check using the CO2 standards specifiedin Section 7.4.3. Make triplicate injections of each gas,and then calculate the average response factor (area/ppm C)for each gas, as well as the overall mean of the responsefactor values. Record the overall mean of the responsefactor values as the CO2 calibration response factor (RFCO2). The RFCO2 must be within 10 percent of the RFNMO.10.1.2.4 System Performance Check. Check the columnseparation and overall performance of the analyzer by makingtriplicate injections of the calibration gases listed inSection 7.4.4. The analyzer performance is acceptable ifthe measured NMO value for each gas (average of triplicateinjections) is within 5 percent of the expected value.10.2 NMO Analyzer Daily Calibration. The followingcalibration procedures shall be performed before andimmediately after the analysis of each set of samples, or ona daily basis, whichever is more stringent:122510.2.1 CO2 Response Factor. Inject triplicatesamples of the high level CO2 calibration gas (Section7.4.3), and calculate the average response factor. Thesystem operation is adequate if the calculated responsefactor is within 5 percent of the RFCO2 calculated during theinitial performance test (Section 10.1.2.3). Use the dailyresponse factor (DRFCO2) for analyzer calibration and thecalculation of measured CO2 concentrations in the ICVsamples.10.2.2 NMO Response Factors. Inject triplicatesamples of the mixed propane calibration cylinder gas(Section 7.4.4.1), and calculate the average NMO responsefactor. The system operation is adequate if the calculatedresponse factor is within 10 percent of the RFNMO calculatedduring the initial performance test (Section 10.1.2.4). Usethe daily response factor (DRFNMO) for analyzer calibrationand calculation of NMO concentrations in the sample tanks.10.3 Sample Tank and ICV Volume. The volume of thegas sampling tanks used must be determined. Determine thetank and ICV volumes by weighing them empty and then filledwith deionized distilled water; weigh to the nearest 5 g,and record the results. Alternatively, measure the volumeof water used to fill them to the nearest 5 ml.11.0 Analytical Procedure.122611.1 Condensate Recovery. See Figure 25-9. Set thecarrier gas flow rate, and heat the catalyst to itsoperating temperature to condition the apparatus.11.1.1 Daily Performance Checks. Each day beforeanalyzing any samples, perform the following tests:11.1.1.1 Leak-Check. With the carrier gas inlets andthe sample recovery valve closed, install a clean condensatetrap in the system, and evacuate the system to 10 mm Hgabsolute pressure or less. Monitor the system pressure for10 minutes. The system is acceptable if the pressure changeis less than 2 mm Hg.11.1.1.2 System Background Test. Adjust the carriergas and auxiliary oxygen flow rate to their normal values of100 cc/min and 150 cc/min, respectively, with the samplerecovery valve in vent position. Using a 10-ml syringe,withdraw a sample from the system effluent through thesyringe port. Inject this sample into the NMO analyzer, andmeasure the CO2 content. The system background isacceptable if the CO2 concentration is less than 10 ppm.11.1.1.3 Oxidation Catalyst Efficiency Check. Conduct a catalyst efficiency test as specified in Section10.1.1.2. If the criterion of this test cannot be met, makethe necessary repairs to the system before proceeding.11.1.2 Condensate Trap CO2 Purge and Sample TankPressurization. 122711.1.2.1 After sampling is completed, the condensatetrap will contain condensed water and organics and a smallvolume of sampled gas. This gas from the stack may containa significant amount of CO2 which must be removed from thecondensate trap before the sample is recovered. This isaccomplished by purging the condensate trap with zero airand collecting the purged gas in the original sample tank.11.1.2.2 Begin with the sample tank and condensatetrap from the test run to be analyzed. Set the four-portvalve of the condensate recovery system in the CO2 purgeposition as shown in Figure 25-9. With the sample tankvalve closed, attach the sample tank to the sample recoverysystem. With the sample recovery valve in the vent positionand the flow control valve fully open, evacuate themanometer or pressure gauge to the vacuum of the sampletank. Next, close the vacuum pump valve, open the sampletank valve, and record the tank pressure.11.1.2.3 Attach the dry ice-cooled condensate trap tothe recovery system, and initiate the purge by switching thesample recovery valve from vent to collect position. Adjustthe flow control valve to maintain atmospheric pressure inthe recovery system. Continue the purge until the CO2concentration of the trap effluent is less than 5 ppm. CO2concentration in the trap effluent should be measured byextracting syringe samples from the recovery system and1228analyzing the samples with the NMO analyzer. This procedureshould be used only after the NDIR response has reached aminimum level. Using a 10-ml syringe, extract a sample fromthe syringe port prior to the NDIR, and inject this sampleinto the NMO analyzer.11.1.2.4 After the completion of the CO2 purge, usethe carrier gas bypass valve to pressurize the sample tankto approximately 1,060 mm Hg absolute pressure with zeroair.11.1.3 Recovery of the Condensate Trap Sample (SeeFigure 25-10).11.1.3.1 Attach the ICV to the sample recoverysystem. With the sample recovery valve in a closedposition, between vent and collect, and the flow control andICV valves fully open, evacuate the manometer or gauge, theconnecting tubing, and the ICV to 10 mm Hg absolutepressure. Close the flow-control and vacuum pump valves.11.1.3.2 Begin auxiliary oxygen flow to the oxidationcatalyst at a rate of 150 cc/min, then switch the four-wayvalve to the trap recovery position and the sample recoveryvalve to collect position. The system should now be set upto operate as indicated in Figure 25-10. After themanometer or pressure gauge begins to register a slightpositive pressure, open the flow control valve. Adjust the1229flow-control valve to maintain atmospheric pressure in thesystem within 10 percent.11.1.3.3 Remove the condensate trap from the dry ice,and allow it to warm to ambient temperature while monitoringthe NDIR response. If, after 5 minutes, the CO2concentration of the catalyst effluent is below 10,000 ppm,discontinue the auxiliary oxygen flow to the oxidationcatalyst. Begin heating the trap by placing it in a furnacepreheated to 200 EC (390 EF). Once heating has begun,carefully monitor the NDIR response to ensure that thecatalyst effluent concentration does not exceed 50,000 ppm. Whenever the CO2 concentration exceeds 50,000 ppm, supplyauxiliary oxygen to the catalyst at the rate of 150 cc/min. Begin heating the tubing that connected the heated samplebox to the condensate trap only after the CO2 concentrationfalls below 10,000 ppm. This tubing may be heated in thesame oven as the condensate trap or with an auxiliary heatsource such as a heat gun. Heating temperature must notexceed 200 EC (390 EF). If a heat gun is used, heat thetubing slowly along its entire length from the upstream endto the downstream end, and repeat the pattern for a total ofthree times. Continue the recovery until the CO2concentration drops to less than 10 ppm as determined bysyringe injection as described under the condensate trap CO2purge procedure (Section 11.1.2).123011.1.3.4 After the sample recovery is completed, usethe carrier gas bypass valve to pressurize the ICV toapproximately 1060 mm Hg absolute pressure with zero air.11.2 Analysis. Once the initial performance test ofthe NMO analyzer has been successfully completed (seeSection 10.1.2) and the daily CO2 and NMO response factorshave been determined (see Section 10.2), proceed with sampleanalysis as follows:11.2.1 Operating Conditions. The carrier gas flowrate is 29.5 cc/min He and 2.2 cc/min O2. The column ovenis heated to 85 EC (185 EF). The order of elution for thesample from the column is CO, CH4, CO2, and NMO.11.2.2 Analysis of Recovered Condensate Sample. Purge the sample loop with sample, and then inject thesample. Under the specified operating conditions, the CO2in the sample will elute in approximately 100 seconds. Assoon as the detector response returns to baseline followingthe CO2 peak, switch the carrier gas flow to backflush, andraise the column oven temperature to 195 EC (380 EF) asrapidly as possible. A rate of 30 EC/min (90 EF) has beenshown to be adequate. Record the value obtained for thecondensible organic material (Ccm) measured as CO2 and anymeasured NMO. Return the column oven temperature to 85 EC(185 EF) in preparation for the next analysis. Analyze eachsample in triplicate, and report the average Ccm.123111.2.3 Analysis of Sample Tank. Perform the analysisas described in Section 11.2.2, but record only the valuemeasured for NMO (Ctm).11.3 Audit Sample Analysis. 11.3.1 When the method is used to analyze samples todemonstrate compliance with a source emission regulation, an audit sample, if available, must be analyzed.11.3.2 Concurrently analyze the audit sample and thecompliance samples in the same manner to evaluate thetechnique of the analyst and the standards preparation. 11.3.3 The same analyst, analytical reagents, andanalytical system must be used for the compliance samplesand the audit sample. If this condition is met, duplicateauditing of subsequent compliance analyses for the sameenforcement agency within a 30-day period is waived. Anaudit sample set may not be used to validate different setsof compliance samples under the jurisdiction of separateenforcement agencies, unless prior arrangements have beenmade with both enforcement agencies.11.4 Audit Sample Results.11.4.1 Calculate the audit sample concentrations and submit results using the instructions provided with theaudit samples. 11.4.2 Report the results of the audit samples andthe compliance determination samples along with their1232identification numbers, and the analysts name to theresponsible enforcement authority. Include this informationwith reports of any subsequent compliance analyses for thesame enforcement authority during the 30-day period.11.4.3 The concentrations of the audit samplesobtained by the analyst must agree within 20 percent of theactual concentration. If the 20-percent specification isnot met, reanalyze the compliance and audit samples, andinclude initial and reanalysis values in the test report.11.4.4 Failure to meet the 20-percent specificationmay require retests until the audit problems are resolved. However, if the audit results do not affect the complianceor noncompliance status of the affected facility, theAdministrator may waive the reanalysis requirement, furtheraudits, or retests and accept the results of the compliancetest. While steps are being taken to resolve audit analysisproblems, the Administrator may also choose to use the datato determine the compliance or noncompliance status of theaffected facility.12.0 Data Analysis and Calculations. Carry out the calculations, retaining at least one extrasignificant figure beyond that of the acquired data. Roundoff figures after final calculations. All equations arewritten using absolute pressure; absolute pressures are1233determined by adding the measured barometric pressure to themeasured gauge or manometer pressure.12.1 Nomenclature.C =TGNMO concentration of the effluent, ppm Cequivalent.Cc =Calculated condensible organic (condensate trap)concentration of the effluent, ppm C equivalent.Ccm = Measured concentration (NMO analyzer) for thecondensate trap ICV, ppm CO2.Ct =Calculated noncondensible organic concentration(sample tank) of the effluent, ppm C equivalent.Ctm = Measured concentration (NMO analyzer) for thesample tank, ppm NMO.F =Sampling flow rate, cc/min.L =Volume of liquid injected, l.M =Molecular weight of the liquid injected, g/g-mole.Mc =TGNMO mass concentration of the effluent, mgC/dsm3.N =Carbon number of the liquid compound injected (N = 12 for decane, N = 6 for hexane).n =Number of data points.Pf =Final pressure of the intermediate collectionvessel, mm Hg absolute.Pb =Barometric pressure, cm Hg.1234Pti = Gas sample tank pressure before sampling, mm Hgabsolute.Pt =Gas sample tank pressure after sampling, butbefore pressurizing, mm Hg absolute.Ptf = Final gas sample tank pressure afterpressurizing, mm Hg absolute.q =Total number of analyzer injections ofintermediate collection vessel during analysis(where k = injection number, 1 . q).r =Total number of analyzer injections of sampletank during analysis (where j = injectionnumber, 1 . r).r =Density of liquid injected, g/cc.Tf =Final temperature of intermediate collectionvessel, EK.Tti = Sample tank temperature before sampling, EK.Tt =Sample tank temperature at completion ofsampling, EK.Ttf = Sample tank temperature after pressurizing, EK.V =Sample tank vo
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